Design of Javanese Gamelan Concert Hall Based on the Value of Acoustic Preference

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ScienceDirect Procedia Engineering 170 (2017) 210 – 216




Engineering Physics International Conference, EPIC 2016

Design of Javanese Gamelan Concert Hall based on the Value of Acoustic Preference
Suyatnoa*, H. A. Tjokronegorob, IGN. Merthayasab, R. Supanggahc, I. Stefanusb, F. Abdalab, J. Sarwonob b

a Department of Physics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia Department of Engineering Physics, Institut Teknologi Bandung, Bandung, Indonesia c Department of Karawitan, Institut Seni Indonesia, Surakarta, Indonesia

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© 2017 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). © 2016 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the organizing committee of the Engineering Physics International Conference 2016 Keywords: Javanese gamelan performance, concert hall, musicians and audience, acoustic parameters

1877-7058 © 2017 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of the Engineering Physics International Conference 2016

doi:10.1016/j.proeng.2017.03.050

Suyatno et al. / Procedia Engineering 170 (2017) 210 – 216

1. Introduction A performance delivers messages to the audience through tone (music) and lyrics, both of which must be heard clearly by the musicians and audience. The clearness of the sounds can be achieved in a room with small reverberation. However, room with low reverberation would not match the traditional sounds of the Javanese gamelan music. Figure 1 shows an example of Javanese gamelan performances at open and semi-open halls, the traditional venue of Javanese gamelan performance.

Figure 1. Javanese gamelan performances in (a). Open hall; (b). Semi-open hall

As shown in Figure 1, Javanese gamelan performances are currently done in open or semi-open hall. This kind of venue is highly dependent on environmental conditions. While, the present of environmental conditions are no able to support the originality of the Javanese gamelan performances. One of them is the presence of an environment noisy and dependence on the weather. One way to reduce the dependence on the weather and a noisy environment is to perform in a closed hall (concert hall). To make Javanese gamelan performances at the closed room, in addition to the acoustic characteristics of the Javanese gamelan and space, the behavior of players and audiences in the performances should also be taken into consideration. The aim is that the acoustic needs of players and audiences can be accommodated, like a performance at the open or semi-open hall. Suyanto et al [1], characterized the acoustics parameters of the Javanese gamelan ricikan which includes frequency, sound envelope, and loudness. These parameters are useful to define the geometry and dimensions of the space that suits the Javanese gamelan performances. In another study, Suyatno [2] reported on acoustic parameters of Pendopo Mangkunegaran Surakarta space, a historical performance space that has produced many artworks related to the Javanese gamelan performances. The reported acoustic parameters include the distribution parameter of Listening Level (LL), Reverberation Time (RT), Inter-Aural Cross Correlation (IACC), Definition (D50) and Clarity (C80). Sarwono [3] established 24.9 ms as the value of Initial Time Delay Gap (ITDG) for Javanese gamelan performances. This parameter relates to the dimensions of the room, especially the placement of reflector to strengthen the voice to the listener's position and also to prevent echoes. In the study conducted by Faris et al [4], the preferred values of acoustic parameters of an audience for Javanese gamelan music were determined using the scoring method for a psychoacoustic test. These parameters include the RT, LL, and ITDG. While in another study, Suyanto [5] used the method of pairwise comparison testing to determine the preferred value for musicians and audiences. Table 1. Acoustic parameters preference for Javanese gamelan performances [5] Parameters RT C80 D50 Bass ratio (BR) Treble Ratio (TR) IACC LL ITDG

Musicians 1.2 s 6.7 dB 75.4 % 0.99 0.92 -

Audiences 1.2 s – 1.6 s 4.0 dB – 6.7 dB 66 % - 75.4 % 0.99 – 1.04 0.7 – 0.92 0.36 – 0.44 69 – 78 dB 40 ms

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Based on the results of the characterization of the source parameter in the show, a value of LL for Javanese gamelan music up to 90 dB or more, depend on the composition and aim of the performances [6]. This value will influence the furthest distance (dimension of a room) between the sources with the audience. This paper discusses the design and simulation of Javanese gamelan concert hall based on acoustic parameters preference by musicians and audience based on Table 1. In part II will be discussed how to obtain the objective acoustic parameters for Javanese gamelan performances from the subjective parameters. Part III, be validated the objective parameters to the architecture design parameter. In part IV, the design simulation result of the Javanese gamelan concert hall, and the last part is a conclusion. 2. Methods To obtain the suitable design space for Javanese gamelan performances that match the criteria of players and spectators, there are several acoustic parameters; both subjective and objective parameters (Table 1). In addition to acoustic parameters, visual parameters and paradigms in enjoying the show also needs to be considered. Figure 2 shows the diagram to design a room for Javanese gamelan performances which suitable for musician and audience acoustic preference.





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Figure 2. Diagram to design the concert hall for Javanese Gamelan

Based on Figure 2, it can be done several approaches acoustic parameters into the parameters of design (architecture), as shown in Table 2. 
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Acoustic parameter

Architecture parameter

LL RT

Shape, room volume, properties material Room Volume, properties material

D50 C80 ITDG

Shape , properties material Shape , properties material Wall and ceiling, Shape, properties material

IACC

Shape , properties material, side wall

Capacity

Shape , room volume

3. Results and Discussion 3.1. Design simulation As performances where often followed, dance and another art performing resulted in the comfort of acoustic and visual from all directions must be fulfilled. One of the models or forms of performances space that suitable for Javanese gamelan is a fanshaped [8]. Figure 2 was shown basic shape the concert hall for Javanese gamelan performances.

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Suyatno et al. / Procedia Engineering 170 (2017) 210 – 216

Figure 2. Basic shape for concert hall Javanese gamelan performances.

Beside to accommodation, the acoustic parameters of Javanese Gamelan (ricikan and ensemble) and the acoustic parameter preferences by players and audience, dimensions, and capacity of the room will affect the absorption of sound in the room, finally caused the reverberation time [7]. The consequence, to achieve conditions of acoustic room corresponding to the functions, hence it needs to the planning of the geometry (shape) the room and the selection of materials properties. But, often to adjust the acoustic parameters (reverberation time) and room volume constrained by the capacity of the room, so was modified by adding a balcony. Besides to increase the room capacity, the addition of a balcony can be control the reverberation time of room by adding the sound absorption. In adding the balcony, which needs to be considered too is the vertical viewing angle of the audience must be more than 40o [8]. Based on consideration of acoustic and non-acoustic parameters of Javanese Gamelan performances, the room for Javanese gamelan performances designed was had base shape is fan shape that 1500 audiences of capacity and 14000 m3 of a volume. Table 3 was shown the detail parameters of the room designed. Table 3. Specification of the room Parameter

Value

Base shape

Fan Shape

Volume

14000 m3

Capacity

1500 audience

Farthest distance from stage

28 m

D/H

0.79

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42o

Figure 3 was shown the shape and dimension of the Javanese gamelan concert hall


 






 


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Figure 3. Dimension and shape off Javanese J gamelan concert hall. (a). Top view. (b). Cross section. (c) 3D view.

3.2. Discussion To determine the direct sound is heard at the farthest distance can be calculated using the equation ⎡ Q ⎤ 2⎥ ⎢⎣ 4πrx ⎥⎦







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Lp x = Lw + 10 log ⎢

With Lpx is the loudness in the x position, Lw is the loudness at a distance of 1 m in front of the source, rx is the distance between the source and the measuring point (x), Q is a factor directions. By using equations (1) and assume that the sound source is located on the surface of the floor with LL value of 90 dB, the loudness at the farthest distance from the source (31 m) is 53 dB. This value will sound fine when prerequisite noise criteria for the concert hall is 20-30 dB [7]. Figure 4 and 5 shows the simulation results of the sound field in the room at a frequency of 1 kHz. The simulation was conducted with 94 dB at 1 m of white noise, where the position is on the stage.







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Figure 4. Mapping distribution of acoustic parameters (a). Listening Level. (b). Reverberation Time (c). Clarity. (d). Definition.




Suyatno et al. / Procedia Engineering 170 (2017) 210 – 216

Figure 5. Acoustics parameter distribution at audience area a). Listening Level. (b). Reverberation Time (c). Clarity. (d). Definition.

Based on Figure 4, the distribution of LL in the audience area are 74-79 dB, and 82-89 dB at the stage. While at the farthest audience is 74 dB. It means that the designs are capable of providing reinforcement of the loudness is 21 dB than to the condition of an anechoic chamber. Distribution parameter of RT at the audience area is 1.0 s - 1.6 s, with an average is 1.3 s. For the parameter, C80 is 4.59 dB and D50 is 52-76%. These parameter values have met the requirements for the concert hall which requires sound clarity, both the instrument sound, and vocal sound. It's caused by at the Javanese Gamelan; these two elements are inseparable and always exist. In addition, it can be used as a concert hall to the sound source (gamelan) at the stage area, the room which designed can also be used for performances of Javanese gamelan to the sound source at the pit. The placement of the sound source in the pit area causes a distance between the source with the audience is shorter. So that modification by adding a barrier between the pit with audience areas is needed. The goal is to reduce the direct sound received by the audience, especially those located near the source (pit). Figure 6 shows the distribution of acoustic parameter in the audience area when the sound source at the pit.

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C

A

B

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Figure 6. Distribution of acoustic parameters when the source at the pit. (a). Listening Level. (b). Reverberation Time (c). Clarity. (d). Definition

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Refer to the Figure 4 and 6, the distribution of acoustic parameters of the room that is designed quite evenly (homogeny). Through these parameters, a musician can maintain communication among the musician, and the audience can enjoy the show like at the original room where the Javanese gamelan was done. 4. Conclusion The design of concert hall for Javanese gamelan performances should still be able to guarantee their acoustic communication among the players, as well as acoustic and visual comfort for the audiences. The room was designed to have 14000 m3 of volume and 1500 audience of capacity with the basic shape is a fan. Base on the simulation, distribution value of the acoustics parameter at the audience plane are 74-79 dB for LL, 1.0 - 1.6 s for RT, 4.59 dB for C80 and 52-76% for D50. Through those parameters, musicians and audiences will expect to obtain the atmosphere and acoustic parameters such as the performances of the open space, where the original Javanese gamelan performances played. Acknowledgements The authors would like to thank the Ristek Dikti, Pendopo Mangkunegaran Surakarta. References [1] Suyatno, H. A. Tjokronegoro, IGN. Merthayasa, R. Supanggah, The acoustics characteristic of Javanese gamelan instruments, case study of the PSTK ITB Javanese gamelan”, (wrote in Indonesian), Physics and Application Seminar, Institut Teknologi Sepuluh Nopember, 2013 [2] Suyatno, H. A. Tjokronegoro, IGN. Merthayasa, R. Supanggah, “Acoustics Parameter Pendopo Mangkunegaran Surakarta for Javanese Gamelan Performance”, Procedia Social and Behavioral Science 184, 322-327, 2015 [3] J. Sarwono, Y.W. Lam, “The Preferred Initial Time Delay Gap And Inter-Aural Cross Correlation For A Javanese Gamelan Performance Hall”, Journal of Sound and Vibration, 2002 [4] A. Fariz, I. Stevanus, J. Sarwono, IGN. Merthayasa, Suyatno, “The Design of Javanese Gamelan Concert Hall Based on Optimum Acoustic Parameters”, International Conference SIA 2015, Universiti Teknologi Malaysia, 2015 [5] Suyatno, H. A. Tjokronegoro, IGN. Merthayasa, R. Supanggah, “Reverberation Time for Musicians and Audience of The Javanese Traditional Gamelan Music”, Icopia, Bali, 2016 [6] Suyatno, H. A. Tjokronegoro, IGN. Merthayasa, R. Supanggah, ”Effect Of Layout Javanese Gamelan Instruments On Stage In Pendhapa Isi Surakarta With Acoustic Parameters For Pengendang”, (wrote in Indonesian), Instrumentation LIPI, Vol 37, No. 2, 2013 [7] L. Beranek, “Concert Hall and Opera House; Musics, Acoustics and Architecture”, 2th edition, Springer, 2004 [8] M. Long, “Architectural Acoustics”, Elsevier Academic Press,2006